1. Field of the Invention
This invention relates to machines used for scarifying, abrading and generally treating the surface of roadways, and more particularly, to a road-cutting apparatus which can be intermittently actuated automatically, as the apparatus moves along the road surface, to create spaced impressions or grooves in the roadway surface while allowing manual compensation for cutter wear.
2. Description of the Prior Art
On the shoulders along roadways, it is frequently a desired option to cut impressions or grooves extending laterally across the shoulder-to act as a warning for drivers that they have moved off the main roadway. When the tires of the vehicle contact the grooves, a noise is heard and vibration is felt which alerts the driver that the tires are in contact with the shoulder. Alternatively, ridges may be laid along the shoulder. In either case, the warning effect is the same, and such devices are frequently referred to as xe2x80x9crumble strips.xe2x80x9d
The spacing of these grooves varies depending upon the locale. For example, some states may use a different spacing than others. Also, in some areas, it is desired to use a larger spacing between groups of grooves. For example, there may be a group of a specific number of grooves which have a relatively small spacing therebetween and then a much larger space between the next set of grooves of that specific number. Generally, this type of spacing is referred to as intermittent cutting.
One prior art device utilizes a cam-like wheel which engages the surface, and as the device moves along the roadway, the cam rotates. This causes a cutter wheel to be alternately lowered into cutting contact with the road surface and raised out of contact. By moving this device along the road surface, a plurality of spaced grooves may be formed. This device has the disadvantage of not easily accommodating intermittent cutting. Also with the cam device, the spacing between adjacent grooves can only be controlled by changing the cam. There is no quick adjustment available. The present invention solves this problem by providing an apparatus which uses a microprocessor to control the spacing between adjacent grooves, and the microprocessor can also be programmed to provide a preset, larger spacing between sets of grooves to allow automatic intermittent cutting.
Another prior art device uses a hydraulic cylinder which raises and lowers the cutter into contact with the road surface. Such a device is disclosed in U.S. Pat. No. 5,415,495. This device has the disadvantage of requiring a highly specialized vehicle of which the cutting apparatus is an integral part. It is not adapted for use with common vehicles, such as farm tractors. The present invention solves this problem by providing a self-contained apparatus which can easily be pulled behind any number of known vehicles, such as farm tractors.
A cutter drum assembly for cutting grooves or impressions in a road surface is disclosed in U.S. Pat. Nos. 5,046,890; 5,129,755; 5,236,278; and 5,378,080. This, or other types of rotary cutters, may be utilized in the apparatus of the present invention.
The present invention also provides an apparatus which can be conveniently moved along a road surface when not in operation but can be quickly and easily placed into an operating position when desired, while at the same time providing automatic cutting of the grooves and also providing control of the cutter to compensate for wear thereon.
The present invention is an apparatus for cutting impressions or grooves in a road surface. The apparatus generally comprises a tool carrier adapted for moving along the road surface, a rotatable cutter positioned adjacent to the tool carrier, a cutter positioning means for positioning the cutter between a raised position spaced from the road surface and an operating position adjacent to the road surface, and a cutter operating means for alternately moving the cutter into and out of cutting engagement with the road surface after the cutter is in the operating position thereof A transport wheel is attached to the tool carrier and has a transport position engaging the road surface and a retracted or raised position spaced from the road surface. A wheel actuation means is used for moving the transport wheel between the transport and retracted positions thereof.
The wheel actuation means comprises a transport control arm pivotally connecting the transport wheel to the tool carrier and a transport cylinder connect to the tool carrier and the transport control arm, whereby the transport control arm and the transport wheel may be pivoted with respect to the tool carrier.
The cutter positioning means comprises a positioning control arm pivotally attached to the tool carrier and a positioning cylinder interconnecting the positioning control arm and the cutter whereby the cutter may be pivoted between the raised and operating pistons thereof The cutter positioning means may be used for pivoting the cutter with respect to the tool carrier for compensating for wear on cutting elements on the cutter.
The cutter operating means comprises an operating control arm attached to the cutter and an operating cylinder interconnecting the positioning control arm and the operating control arm whereby the cutter may be engaged and disengaged with the road surface. The cutter operating means is adapted for pivoting the cutter with respect to the tool carrier when moving the cutter between cutting engagement with the road surface and disengagement therefrom.
The apparatus further comprises an elevating wheel connected to the cutter for supporting the cutter on the road surface when the cutter is in the operating position thereof and when the cutter is cuttingly engaged with the road surface. The elevating wheel is connected to the positioning control arm and pivotable therewith.
Preferably, the apparatus further comprises a means for measuring a distance the tool carrier is moved along the road surface and generating a signal in response thereto and a logic controller actuating the cutter operating means in response to the signal. This may be used to control the width and depths of the grooves or impressions and also the spacing therebetween. It may also be used to control the longer spacing between groups of grooves or impressions during intermittent cutting.
Numerous objects and advantages of the invention will become apparent as the following detailed description of the preferred embodiment is read in conjunction with the drawings which illustrate such embodiment.